Previously, we developed a coin counting variable telling us how many coins are in the scene. However, regardless of the count, the player still can't collect the coins during gameplay. Let's fix this now. To start, we need to think about collisions. Thinking carefully, we know that a coin is considered collected whenever the player walks into it, that is, a coin is collected when the player and the coin intersect or collide.
To determine when a collision happens like that, we must approximate the volume of both the player and coin in order to determine when the two volumes overlap in space. This is achieved in Unity through colliders. Colliders are special physics objects attached to meshes. They tell us when two meshes intersect. The FPSController object (First-person controller) already has a collider on it, through its Character Controller component. This approximates the physical body of a generic person. This can be confirmed by selecting FPSController in the Scene...